Earlier on today, I was working on a model, and decided I didn't like what I did, so I CTRL-Z'ed my actions (it was undoing mostly moving points and lines, connecting points with lines, and dividing lines), until the point where it had stopped responding (that seems to happen alot). So I let it sit, and eventually I had to CTRL-Alt-Deleted it to close it (like usual)...

When I regained my composure and decided to work on it again, I loaded 3d canvas, only to see "Configuring 3d Canvas" and all the stuff that pops up when you've run 3d canvas for the first time... including seeing "Freeware version" on the startup popup.

I've had 3DC crash in rare instances where the Windows registry get's "touched" innapropriately. Since this information is stored in the registry, it makes sense that it might have gotten trashed when it crashed.